Broken Symmetry, Helix, and Skyrmion in B20 Chiral Magnets

C. L. Chien
Department of Physics and Astronomy The Johns Hopkins University

日期: 6月18日(周三）下午3:00
地点: 唐仲英楼B501

摘要：
Broken symmetry, a fundamental concept in many braches of physics, is consequential in crystalline solids. In cubic B20 magnets (e.g., MnSi, FeGe, Cu2OSeO3), the broken inversion symmetry leads to the Dzyaloshinskii-Moriya (D-M) interaction, which gives rise to the helical ground state and the exotic Skyrmion state as previously revealed by small angle neutron scattering (SANS)1 in the reciprocal space and Lorentz transmission electron microscopy (TEM)2 in the real space. We use magnetometry and transport measurements to capture the signature of the broken rotation symmetry, the non-collinear spin structures3, and the intrinsic resistance of spin helix4.

1 S. Mühlbauer et al., Science 323, 915 (2009).
2 X. Z. Yu, et al., Nature 465, 901 (2010).
3 S. X. Huang and C. L. Chien, Phys. Rev. Lett. 108, 267201 (2012).
4 S. X. Huang et al., (submitted).